Development/history of Mesoscopic Physics/quantum transport I am studying mesoscopic physics/quantum transport. Now I am wondering (out of interest): how did this field emerge and what made it such a huge field? I couldn't find this somewhere clear on the web and my book lacks an intro in which this is explained.
 A: This is a really interesting question, and I've no precise answer... So let me just tell you a few random things.
First, I'd like to say that mesoscopic physics emerges simply because it was technologically available, as most of the emerging field actually. It is indeed a big field, also because of its potential industrial interests (the famous nanoscale = macrosale idiom). Isn't the transistor the most created artificial object in the world after all ? 
History for mesoscopic physics is difficult to trace back in time, for it has always existed somehow. People would say it started in  the mid-60's, when Landauer discussed how tunnelling between contacted elements lead to the usual Ohm's law when multiplying the elements -- R. Landauer, Spatial Variation of Currents and Fields Due to Localized Scatterers in Metallic Conduction IBM J. Res. Dev. 1, 223 (1957). At that time quantisation of channel and adiabatic transport in nanostructure were elaborated, and a bit later (if I remember correctly, I do not know the original paper for this) Coulomb blockade was discussed. Once again, you see Landauer was working at IBM-lab, so you can understand his interest in electronic transport in small structures.
Nevertheless, it is clear that tunnelling was already known since the early days of quantum mechanics, and the transport properties were always of interest in condensed matter. So mesoscopic physics is really the science of transport when the phase coherence length is longer than the size of the structure. Defined that way, mesoscopic physics emerges with Josephson junctions, so you can really, exactly say it started in 1962 (see errata below). But people would disagree on this I guess, for mesoscopic physics is not only about superconductivity. An other definition for mesoscopic physics could be: the physics the scale of which allows for single electron detection. According to this definition, the first experimental setup was clearly a quantum-dot with quantised conductance: B. van Wees, H. van Houten, C. Beenakker, J. Williamson, L. Kouwenhoven, D. van der Marel, and C. Foxon, Quantized conductance of point contacts in a two-dimensional electron gas. Phys. Rev. Lett. 60, 848 (1988).

Errata: my remark concerning the Josephson effect is not entirely correct. Indeed, in the historical introduction, Josephson was interested in incoherent process, say. Then he discussed the case of what is now called a S/I/S system, with the middle part being an insulator (I), sandwiched between two superconductors (S). Then it is clear that the insulator forbids the passage of charge, and that the propagation of quasi-particles is not really coherent in the modern sense. Only in the beginning of the 90's people realised that one can use S/N/S (N=normal) systems instead of S/I/S, in which case the coherent current is explained in terms of Andreev channels/modes. The original papers about S/N/S systems are C. W. J. Beenakker and H. van Houten, Phys. Rev. Lett. 66, 3056 (1991) and A. Furusaki and M. Tsukada, Solid State Commun. 78, 299 (1991).

It is also interesting to realise that in the mid-60's it was in the air to go to lower scales. Quantum mechanics arrived to a well established playground, especially in many-body problem, when it successfully explained semi-conducting and super-conducting properties. So the next great question was: why does quantum mechanics rule the world of electrons ? And then people started being interested in decoherence and all that stuff. In parallel, interest in quantum computation and quantum simulation grew, and now we have this huge field.
I believe mesoscopic physics now grows up quickly because of its promises: quantum computer, classical to quantum and quantum to classical transitions, topological properties, to cite only a few of them. This, its potential industrial consequences, and of course the fascination for publications of the new generations of researchers explain why this field still grows.
To conclude, there is a (tentative) historical introduction in the book by Nazarov and Blanter: Quantum transport, introduction to nanoscience, Cambridge University Press (2009).
A: Here is a good introduction to the history of mesoscopic physics. 
